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All Outputs (22)

On two conjectures of Sun concerning Apéry-like series (2023)
Journal Article
Charlton, S., Gangl, H., Lai, L., Xu, C., & Zhao, J. (2023). On two conjectures of Sun concerning Apéry-like series. Forum Mathematicum, 35(6), 1533-1547. https://doi.org/10.1515/forum-2022-0325

We prove two conjectural identities of Z.-W. Sun concerning Apéry-like series. One of the series is alternating, whereas the other one is not. Our main strategy is to convert the series and the alternating series to log-sine-cosine and log-sinh-cosh... Read More about On two conjectures of Sun concerning Apéry-like series.

On functional equations for Nielsen polylogarithms (2021)
Journal Article
Charlton, S., Gangl, H., & Radchenko, D. (2021). On functional equations for Nielsen polylogarithms. Communications in Number Theory and Physics, 15(2), 363-454. https://doi.org/10.4310/cntp.2021.v15.n2.a4

We derive new functional equations for Nielsen polylogarithms. We show that, when viewed moduloLi5 and products of lower weight functions, the weight 5 Nielsen polylogarithm S3,2 satisfies the dilogarithm five-term relation. We also give some functio... Read More about On functional equations for Nielsen polylogarithms.

Hyperbolic tessellations and generators of for imaginary quadratic fields (2021)
Journal Article
Burns, D., de Jeu, R., Gangl, H., Rahm, A. D., & Yasaki, D. (2021). Hyperbolic tessellations and generators of for imaginary quadratic fields. Forum of Mathematics, Sigma, 9, Article e40. https://doi.org/10.1017/fms.2021.9

We develop methods for constructing explicit generators, modulo torsion, of the K3 -groups of imaginary quadratic number fields. These methods are based on either tessellations of hyperbolic 3 -space or on direct calculations in suitable pre-Bloch gr... Read More about Hyperbolic tessellations and generators of for imaginary quadratic fields.

On the topological computation of K_4 of the Gaussian and Eisenstein integers (2018)
Journal Article
Gangl, H., Dutour Sikiriˇc, M., Gunnells, P., Hanke, J., Schuermann, A., & Yasaki, D. (2019). On the topological computation of K_4 of the Gaussian and Eisenstein integers. Journal of Homotopy and Related Structures, 14, 281-291. https://doi.org/10.1007/s40062-018-0212-8

In this paper we use topological tools to investigate the structure of the algebraic K-groups K4(R) for R=Z[i] and R=Z[ρ] where i:=−1−−−√ and ρ:=(1+−3−−−√)/2. We exploit the close connection between homology groups of GLn(R) for n≤5 and those of rela... Read More about On the topological computation of K_4 of the Gaussian and Eisenstein integers.

On the Broadhurst-Kreimer generating series for multiple zeta values (2015)
Book Chapter
Carr, S., Gangl, H., & Schneps, L. (2015). On the Broadhurst-Kreimer generating series for multiple zeta values. In L. Álvarez-Cónsul, J. Burgos Gil, & K. Ebrahimi-Fard (Eds.), Feynman amplitudes, periods, and motives : international research conference on periods and motives : a modern perspective on renormalization : July 2-6, 2012, Institute de Ciencias Matemáticas, Madrid, Spain (57-77). American Mathematical Society. https://doi.org/10.1090/conm/648/12998

Multiple polylogarithms, polygons, trees and algebraic cycles. (2009)
Book Chapter
Gangl, H., Goncharov, A., & Levin, A. (2009). Multiple polylogarithms, polygons, trees and algebraic cycles. In D. Abramovich, A. Bertram, L. Katzarkov, R. Pandharipande, & M. Thaddeus (Eds.), Algebraic geometry--Seattle 2005. Part 2 (547-593). American Mathematical Society

Multiple logarithms, trees and algebraic cycles (2007)
Book Chapter
Gangl, H., Goncharov, A., & Levin, A. (2007). Multiple logarithms, trees and algebraic cycles. In P. Cartier, B. Julia, P. Moussa, & P. Vanhove (Eds.), Frontiers in Number Theory, Physics and Geometry II (759-774). (New ed.). Springer Verlag

The differential properties of multiple logarithms and those of corresponding algebraic cycles are related to the combinatorics of certain trees.

Double zeta values and modular forms (2006)
Presentation / Conference Contribution
Gangl, H., Kaneko, M., & Zagier, D. (2006). Double zeta values and modular forms. In J. J. García de Leonardo, J. Tronch Pérez, M. del Saz Rubio, C. Manuel Cuenca, B. Pennock Speck, & M. J. Coperías Aguilar (Eds.), Automorphic forms and zeta functions : proceedings of the conference in memory of Tsuneo Arakawa, 4-7 September 2004, Rikkyo University, Japan (71-106)

We give new relations among double zeta values and show that the structure of the Q-vector space of all (known) relations among double zeta values of weight k is connected in many different ways with the structure of the space of modular forms of wei... Read More about Double zeta values and modular forms.

Generators and Relations for K_2 O_F (2004)
Journal Article
Belabas, K., & Gangl, H. (2004). Generators and Relations for K_2 O_F. K-Theory, 31(3), 195 - 231. https://doi.org/10.1023/b%3Akthe.0000028979.91416.00

Tate's algorithm for computing K_2 O_F for rings of integers in a number field has been adapted for the computer and gives explicit generators for the group and sharp bounds on their order---the latter, together with some structural results on the p-... Read More about Generators and Relations for K_2 O_F.

Functional equations for higher logarithms (2003)
Journal Article
Gangl, H. (2003). Functional equations for higher logarithms. Selecta Mathematica (New Series), 9(3), 361 - 377. https://doi.org/10.1007/s00029-003-0312-z

Following earlier work by Abel and others, Kummer gave in 1840 functional equations for the polylogarithm function Li_m(z) up to m = 5, but no example for larger m was known until recently. We give the first genuine 2-variable functional equation for... Read More about Functional equations for higher logarithms.